P, Q and R share profits equally. At the time of P's retirement, goodwill appears in the books at $\text{Rs. }3000$. P will be debited with what amount for his share of existing Goodwill?

When goodwill already appears in the books of accounts at the time of a partner's retirement, it must be written off among all the old partners in their old profit-sharing ratio.The old profit-sharing ratio among P, Q, and R is equal, i.e., $1:1:1$.The total amount of existing goodwill to be written off = $\text{Rs. }3000$.
$$\text{P’s share of existing goodwill}=\text{Rs. }3000\times \frac{1}{3}=\text{Rs. }1000$$
The journal entry to write off the existing goodwill is:
$$\text{P’s Capital A/c Dr. Rs. }1000$$
$$\text{Q’s Capital A/c Dr. Rs. }1000$$
$$\text{R’s Capital A/c Dr. Rs. }1000$$
$$\text{To Goodwill A/c Rs. }3000$$
Therefore, P's account will be debited with $\text{Rs. }1000$.